Orcus Patera

Orcus Patera is a region on the surface of the planet Mars first imaged by Mariner 4.[1] It is a depression about 380 km long, 140 km wide, and about 0.5 km (500 meters) deep but with a relatively smooth floor.[2] It has a rim up to 1.8 km high.[2] Orcus Patera is west of Mons Olympus and east of Elysium Mons.[2] It is about half-way between those two volcanoes, and east and north of Gale crater.

It has experienced aeolian processes, and has some small craters and graben structures.[2] However, it is not known how the patera originally formed.[2] Theories include volcanic, tectonic, or cratering events.[2]